There is no way a state can deny the implementation of the Citizenship Amendment Act when it is already passed by Parliament, said Congress leader Kapil Sibal on Saturday, who claimed that doing so would be “unconstitutional”.

“If the CAA is passed, no state can say ‘I will not implement it’. It is not possible and is unconstitutional. You can oppose it; you can pass a resolution in the Assembly and ask the central government to withdraw it.

“But constitutionally saying that I won’t implement it is going to be problematic and going to create more difficulties,” said the former minister of law and justice on the third day of the Kerala Literature Festival .

It was the first state government to challenge the act and the Kerala Assembly was the first to pass a resolution against the law. Following in the southern state’s footsteps, the Punjab Assembly on Friday passed a resolution demanding to scrap the contentious law.

Several states, including Kerala, Rajasthan, Madhya Pradesh, West Bengal and Maharashtra have voiced their disagreement with the CAA as well as National Register of Citizens and National Population Register.

“So, what is being said is that we would not allow a state-level officer to cooperate with the Union of India. That is what is being said; practically, if this is possible or not, I am not sure. But constitutionally, it would be very difficult for the state government to say that I will not follow a law passed by Parliament,” he explained.